Critical periods of early development created by the coordinate modulation of ion channel properties.

The development of ion channel properties in excitable cells begins in the very early embryo and continues throughout differentiation. The pattern of ion channel development in a given cell type is not a simple linear progression to the mature state, but rather is a complex sequence of modulatory events that create windows of time during which excitability is qualitatively different from that in the mature cell. These windows are likely candidates for critical periods when electrical activity influences later development.